That's the thing, clones aren't cheap. They project the price of manufacturing a knife (in China) and then selling it with a normal profit margin (including international shipping).
That is the price of a knife minus marketing, ads, branding, warranty (that you might never use), etc.
Add 15% to a designer (if any designer would agree to cooperate) and you still don't scratch the genuine knife prices.
It's like when you see a product on Ali for a few bucks and then see the same one on Amazon (with the same picture), but someone wrote a sophisticated brand name for it and sells it for 4x the price. Then you ask: "Why is the other one so cheap?"
It's not. That's what it's supposed to cost.
I'd argue that those things are part of the inherent cost of a/any knife. If I understand your argument correctly, you're saying that these are extra costs associated with purchasing a brand-name blade as opposed to the much lower cost of a clone where one would only be paying for the manufacturing and perhaps shipping?
However (to myself at least, and I suspect I may not be alone here), with maybe the exception of paying for a brand name, paying for these associated costs is fair in my eyes. When a company spends money and many hours doing R&D for a product, in this case a knife, they're obviously going to want it to sell so they can make a profit off of it (how all for-profit businesses operate I'd imagine). This in turn means making the public aware of this new and awesome product they've put together over time that's been given a lot of effort - hence the necessity of marketing and ads. The more people that know about the product, the chances are that more people are going to buy it because how can someone buy something that they don't even know exists? We should also want our favourite knife companies to move their products because their health is good for our hobby and the industry.
As for the warranty, it's basically insurance. You hope you won't ever need it, but if you do, thank god it's there!
Bringing this back to clones, the flaws that I see in your argument relating to the associated costs mentioned above are:
1) You pay for the marketing in a brand name knife and you according to you, one wouldn't when purchasing a clone.
HOWEVER, that's not to say there isn't any marketing for the clone - the clone gets some pretty good free marketing from the company that they're "borrowing" the design from. Using Spyderco as an example, they market their designs and promote them to us consumers. When someone stumbles across their products/marketing but decides not to purchase a knife from them due to cost for example, but they're willing to pull the trigger on the clone they found online because its a cheaper alternative that still allows them to buy into some/all of the benefits of the design then the popularity/reputation/marketing of Spyderco surely had a hand in this clone's purchase somewhere did it not? This is not to say everyone who buys a clone is looking for a cheaper alternative to the original or that you can't buy a clone without knowing about the original, but it would seem to me clones don't need advertising because they are piggy-backing off of the advertising/marketing/popularity of the original. So in essence you're not paying for advertising with a clone because they're "borrowing" that too.
2) You may not ever need to use a warranty service. I may not ever need to use a warranty service. But there are certainly a great many that have used one and there will be many more that will use a warranty service in the future. We always hope that with anything, the product was made right so it doesn't have to be "made right," but this is clearly not always the case. And it could be argued that instead of forcing someone to pay for warranty service by building the cost into the knife when makers and manufacturers could simply drop the price, but I have two problems with this. The first of which is it creates a disposable mentality which is not the greatest for the environment. Alternatively, materials and F&F still need to be paid for in a knife among other things and the higher-end the materials are and the greater the level of F&F is, removing the cost of the warranty only does so much to affect the price. If a $600 knife was able to be sold for $500 or even $400 because you were no longer paying for that pesky warranty, then if you had a problem with the knife that you couldn't fix yourself, would you be able to just chuck it away with the mentality of "It's fine, I'll just buy a new one"? Even if you're buying clones that were $10-$20 a pop and you didn't care if they lasted a lifetime or a couple months, by the time you bought your 3rd or 4th clone because of this problem or that problem, wouldn't you have just been better off buying an inexpensive $30 dollar knife from a company that had an awesome warranty? Even if you've had your $20 clone for a few years with no problems, it also says something about a company when they are willing to stand behind their product, whether its their $30 knife or their $300 knife, and personally, the piece of mind is again, worth the price of admission for me.
I'm not necessarily attacking the clones themselves here, but what I am trying to do is tell you that those "extraneous" costs that you associated with brand name knives aren't as unneeded as you may think. At the very least, they aren't unwarrated to me.